Glycine max (L.) Merr., including soybean and black soybean, is one of the most important sources of oil and proteins in the world. For instance, soybeans can be processed to obtain edible oil that is used as salad oil, or for manufacture of margarine and shortening. Soybean oil can be also used in the manufacture of paints, linoleum, oilcloth, printing inks, soaps, insecticides, and disinfectants. Besides, lecithin phospholipids obtained from the by-products of the oil industry, can be used as wetting and stabilizing agents in food, cosmetics, pharmaceuticals, leathers, paints, plastics, soaps, and detergents. Soy meal is a very protein-rich feeding stuff for livestock. In addition, soybean protein can be used in manufacture of synthetic fibers, adhesives, textile sizing, waterproofing, fire-fighting foams and so on.
In medical use, soybeans have been reported to have effects on many diseases.
Soybean can be used as a nutritious supplement for regulating the functions of bowels, heart, kidney, liver, and stomach. Since soybean oil contains a high amount of unsaturated fatty acids, it can be used to combat hypercholesteremia. Medical lecithin from soybeans functions as a lipotropic agent. In addition, tigmasterol known as an antistiffness factor, and sitosterol used as a replacement for diosgenin in some antihypertensive drugs, are prepared from soybeans. Isoflavones and phyto-oesterogens found in soybeans have been suggested to have a preventive effect against various cancers comprising breast, prostate, and colon cancers (Adlercreutz, H.; Phyto-oestrogens and cancer. The Lancet Oncology, 2002, Vol. 3, p. 364-373). Other literature indicates that in order to achieve the effect on preventing the occurrence of breast cancer of isoflavones, at least 100 mg daily dose should be consumed continually for a month, and it represents that only by being consumed continually at the high dose, isoflavones exhibit anti-cancer effect (Lu L J, Anderson K E, Grady J J, Nagamani M.; Effects of soya consumption for one month on steroid hormones in premenopausal women: implications for breast cancer risk reduction. Cancer Epidemiol Biomarkers Prev. 1996 January; 5(1): 6370). Consumption of phytosterol-supplemented margarine is also found to lower total plasma cholesterol and LDL-cholesterol concentrations in older middle-aged hypercholesterolemic individuals (Matvienko, O. A., Lewis, D. S., Swanson, M., Aendt, B., Rainwater, D. L., Stewart, J., and Alekel, D. L.; A single daily dose of soybean phytosterols in ground beef decreases serum total cholesterol and LDL cholesterol in young, mildly hypercholesterolemic men. Am J Clin Nutr., 2002, 76, p. 57 64).
Some extracts from soybean have been also reported to have pharmaceutical effects. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of 70% aqueous acetone extract from the seed coat of a brown soybean variety, Akita-Zairai, is disclosed (Takahata, Y., O.-Kameyama, M., Furuta, S., Takahashi, M., and Suda, 1.; Highly polymerized procyanidins in brown soybean seed coat with a high radical-scavenging activity. J. Agric. Food Chem., 2001, 49, p. 5843 5847). An extract from germ extracts, soybean, rice bran, tear grass, sesame, wheat, citron, green tea, green leaf extract, and malted rice, which are slowly roasted under a temperature at less than 60° C. and fermented with Aspergillus oryzae over 3 days to transform each ingredient into low molecular weight substances, is found to have antioxidative effects (Minamiyama, Y., Yoshikawa, T., Tanigawa, T., Takahashi, S., Naito, Y., Ichikawa, H., and Kondo, M.; Antioxidative effects of a processed grain food. J. Nutr. Sci. Vitaminol., 1994, 40, p. 467 477). Water extract of black soybean is also reported to effect on acetaminophen-induced liver injury by measuring serum glutamate-oxalate-transaminase (sGOT) and serum glutamate-pyruvate-transaminase (sGPT) activities in rats (Wu, S.-J., Wang, J.-S. and Chang, C.-H.; Evaluation of hepatoprotective activity of legumes. Phytomedicine, 2001, Vol. 8(3), p. 213 219).
Some specific extracts from soybean have been found to be applied in cosmetics or pharmaceuticals in treating some skin diseases. A soya extract, which contains sphingomyelins and phospholipids in defined ratios is disclosed to be used in cosmetics for the treatment of dry skin (U.S. Patent Pub. No. US2002/0009509 A1). Such extract is produced by extracting ripe whole soya beans or oil-free soya flour using aliphatic alcohols alone or in a mixture with water and followed by the treatment with aliphatic hydrocarbons and with aliphatic ketones. Therefore, the extract is liposoluble.
An acne medicine, cosmetic production inhibitor or cosmetic composition containing one or more plant extracts selected from whey, and a Phellodendeon amurense Ruprecht extract, and further one or more extracts selected from Scutellaria baicalensis Geoegi, Symphytum officinale Linne, and Glycine max (L.) Merrill, is found to be effective on preventing or treating skin diseases such as acne or inflammatory chapped skin caused by the acne (JP Patent No. 2001097842).
Products of fermenting soybean by microorganisms are also applied as anti-active oxygen action compositions, agents, foods, cosmetics and medicines (such as JP Patent No. 4139132).
Although many uses of soybeans have been reported, different applications of soybean extract are yet to be developed.